What is bendy and flexible?

[Sharpy]

Some time ago, Spider engines were used as hinges, as joints created by attaching spider to, say, cargo bay, then another spider to the first, then the loading platform to the second would create a joint that would bend even 90 degrees under the cargo ramp weight alone.

Now I tried this technique and it doesn't seem to work - a stack of five spiders doesn't bend to a significant degree under the load of an orange tank...

Are there any other parts that make very bendy joints?

[Sharpy]

Scratch that. Autostrut kicked in. Spiders still work, but not for wheels.